Techniques for using plasma to improve the fuel in an internal-combustion engine have been investigated.
For example, an internal-combustion engine in which the fuel is reformed using a plasma electrode is disclosed in Patent Document 1. In this internal-combustion engine, the fuel is introduced into a fuel-reforming vessel, and the fuel is reformed by a plasma electrode provided therein and ejected by an injector.
An internal-combustion engine provided with a fuel-reforming mechanism in which exhaust gas recirculation (EGR) is employed is disclosed in Patent Document 2. In this internal-combustion engine, a part of the exhaust gas from a three-way catalyst is added to the fuel, and the fuel is lightened using a plasma reactor composed of a mesh electrode and returned to the combustion chamber.    [Patent Document 1] Japanese Laid-open Patent Application No. 2007-09778    [Patent Document 2] Japanese Laid-open Patent Application No. 2005-98226